TRIM Enabler is what you are looking for.
However, Sandforce drives like the one you have listed have some of the best garbage collection in the industry. It isn't really necessary to have TRIM enabled, it was merely to fix the issues that early drives had with their poor garbage collection. That isn't to say TRIM is useless now, however.
As for the drive that you have selected, Sandforce drives are known for being unreliable, with crashing issues being experienced by many users. I'd consider looking at the always-recommended Crucial m4. All SSDs are so fast nowadays that the slower speeds won't really make that much of a difference (and also, read performance on the m4 in some situations is better).
Garbage collection on these drives isn't quite as good as on the Sandforce drives, however, again you probably won't need TRIM unless you are doing a hell of a lot of writes and deletes.